logical-fallacy-review

name	logical-fallacy-review
description	Use when evaluating whether premises in plans, ADRs, reviews, security justifications or agent recommendations validly support their conclusions — for logical fallacies, not judgement distortion from cognitive bias.
aliases	["avoid-fallacies","avoid-logical-fallacies","logical-fallacy-check","argument-quality-review","adr-reasoning-review","false-dichotomy-check"]

Logical Fallacy Review

When to use

Use this skill after an initial implementation plan, architecture option set, review comment, risk justification or recommendation exists and quality matters. Apply it when reasoning chains influence merge decisions, security posture, scope cuts, incident root cause, test strategy or tool selection.

Fallacy review complements deterministic validation; invalid rhetoric does not override failing tests or policy gates.

When not to use

Do not use this skill when the task is purely syntactic or already decided by executable checks alone. Do not treat fallacy spotting as a substitute for reproduction steps, metrics or contract tests. Do not use it for ranking bias or estimate distortion — use cognitive-bias-review. Do not use it as the primary critique loop when tests and linters have not yet run — use reflection-and-verification first.

Objective

Identify logical fallacies in technical arguments so conclusions follow from valid evidence and explicit premises rather than rhetorical force or missing steps.

Procedure

1. Extract the claim, stated premises and intended conclusion from the artefact.
2. Check whether the conclusion follows from the premises or smuggles unstated assumptions.
3. Scan for common fallacies using the checklist below; cite the exact phrase or reasoning gap.
4. Repair the argument: add missing premises, narrow the claim, gather evidence, or reject the conclusion.
5. Re-run deterministic checks where the fallacy affected a technical decision (tests, threat model, benchmarks).
6. Record unresolved logical gaps and whether the decision should be deferred or escalated.

Fallacy checklist (engineering contexts)

• False dichotomy: presenting only two options when more exist (for example rewrite vs do nothing).
• Straw man: attacking a weaker version of an alternative design or review comment.
• Hasty generalisation: inferring universal rules from one repo, one incident or one flaky test run.
• Appeal to authority / popularity: choosing a stack or pattern because it is fashionable without local fit evidence.
• Sunk-cost fallacy: continuing a path because effort was already invested despite new evidence that another option is better.
• Slippery slope: claiming a small change inevitably leads to catastrophic outcomes without causal steps.
• Circular reasoning: using the conclusion as its own premise (for example “it is safe because we always do it this way”).
• Post hoc ergo propter hoc: assuming A caused B because B followed A in time without isolation evidence.
• Moving the goalposts: changing success criteria after results are known to preserve a preferred outcome.
• Red herring: introducing irrelevant concerns to avoid addressing the actual defect or trade-off.

Related skills

• cognitive-bias-review — judgement distortion under uncertainty
• reflection-and-verification — bounded critique and repair loops with deterministic checks first
• reasoning-techniques — decomposition and alternative-path exploration
• documentation-and-adrs — durable decision records with explicit options and consequences
• code-review-and-quality — review comments grounded in verifiable defects
• threat-modeling — security justifications that need valid causal reasoning

References

• Fallacy (Wikipedia)
• List of fallacies (Wikipedia)

Verification

• Claim, premises and conclusion are explicitly separated.
• Identified fallacies reference concrete text or reasoning gaps.
• Repaired arguments include testable or measurable evidence where possible.
• Decisions deferred or escalated when logic remains invalid and impact is material.
• Residual logical uncertainty is documented.